I've come here in the hope to get some closed ecosystem advice and hints.Recently I’ve read the following post on a different site: slashdot

To me that sounds pretty cool and got me thinking; Can I do something similar but cooler/more elaborate? I’ve decided to atleast attempt it.. except I want more than a plant / fungus “loop”. But what to pick / put in?I’ve had a look around and found this: ecosphereDoesn’t look too bad, but the loop is rather simple (see here) plus I’ve read the shrimp die after ~3 years (source). So it’s not a fully self-sustainable ecosystem but more of a slowly dying one…

I think the coolest would be some swamp/mangrove ecosystem. I came up with the following. In the water (~10cm?): algae + shrimp/seamonkies + bacteria. Some swamp/mangrove plant half in the water, half sticking out. Fruit flies flying around.However as I lack bio/eco-knowledge, so I have no idea if that would work, work as in, be stable and self-sustainable. Plus I miss details on which plants/species/etc would be the best for this.

What if an organism goes through explosive reproduction rate, resulting in cannabalism when there is no food left? Will the plant outgrow the jar? Fruitflies too dumb to not drown? Plant(s) growing fast, blocking the sunlight from the algae? etc etc.. plenty of questions/problems/variables. Is it even possible to make any predictions or is the only way to go here Trial & Error? Is it even possible at all?

While this is a cool science project on its own, I am partially going for looks too.. hence I want small critters in it so it's somewhat interesting/cool to look at. So active critters.. plus if there is water it shouldnt get too muddy.

I think 25L is a good size and the 5” opening should be big enough for me to get everything inside. If someone has a better glass jar or something similar, please let me know (even better if it’s from a Dutch (online) shop).

I am also very interested in this topic~ 'Closed-cell Ecosystem's'!! I have been thinking about it for several years now, and believe a system with fish and some water based plants at the end of it are key.

There have been articles in popular science within the last couple years about creating city buildings- (average size builiding in city, 15-20 stories) that would recycle all the water for the entire block, provide fish and rice, use solid waste to fire incinerator that produces quit a bit of energy...

but for the private, in home experiment... ??

I recently put this topic in front of my science club, our first meeting...as I am at a college with a good biology program, and most of the members of the group are that major, I am hoping to get some 'groupthink' in on good sound closed cell biology/ecology of these 'closed-cell ecossystems'...

I am interested in this topic because it currently takes two tons of 'stuff' per month for us to exist at the international space station;if we are ever to even travel to mars we have to get over this 'brown-bag lunch' program we are on...if it takes us three years to get to mars and back, and lets just say we can have stuff waiting for us on mars,we still need at least 14 months worth of 'stuff' (stuff being our air, water and food we need to survive, mostly)

So that is: 14 x 2tons= 28 tons of 'brown bag lunches' in order to just get to Mars.these numbers get hard to transport-

We have to be able to bring a system along with us that replenishes our air, and water, and hopefully utilizes the energy in our waste.Not to mention would hopefully provide food-Creating a 'Closed-Cell Ecosystem' is the biggest obstacle we have to space travel at this point..

Well, I think fishes are not so good, because they have quite long life-span, probably something with rather shorter life-span would be more usefull.

As you mentioned the cities with rice and fishes produced, (unless you won't use the new GM triploid fishes) you need several months to grow rice and few years to grow the fishes. For that you need lot of place to provide the material all the time.

All materials will need to be transported from Earth, the Moon, the asteroids, comets, or other planets and their moons. Thus, the space colony designer may assume ample energy but must conserve materials. Therefore, the life support system of the colony should recycle all materials. Since we would prefer a life support system consisting primarily of plants, animals, and single-celled organisms, our life support system may be described as an ecosystem. Because our space colony's ecosystem is does not import or export materials, we call it a closed ecosystem.